sawyer



2 Sheets-Sheet 1.

(No ModeL) H. SAWYER.

CRANE.

. Patented Nov. 15, 1892'.

UNITED STATES PAT NT OFFICE.

HARRY SAVVYER, OF MUSKEGON,MICHIGAN,ASSIGNOR TO THE SHAW ELECTRIC CRANECOMPANY, OF SAME PLACE.

CRAN E.

SPECIFICATION forming part of Letters Patent N 0. 486,412, datedNovember 15, 1892.

Application filed July 20, 1892. Serial No. 440,686. (No model.)

To all whom it may concern:

- Be it known that I, HARRY SAWYER, of Mnskegon, in the county ofMuskegon and State of Michigan, have invented certain new and usefulImprovements in J ib-Oranes; and I do hereby declare that the followingis a full, clear, and exact description of the invention, which willenable others skilled in the art to which it pertains to make and usethe same, reference being had to the accompanying drawings, and to theletters of reference marked thereon, which form a part of thisspecification.

The main object of my invention is to secure a horizontal movement ofthe suspended load in extending or withdrawing the upper end of the jibmore or less as to the mast and in turning it about the mast.

It consists, essentially, of certain novel features in the arrangementof the hoisting mechanism by which the foregoing object is attained.

In the accompanying drawings like letters designate the same parts inthe several figures.

Figure 1 is a side elevation of a jib-crane to which myimprovements areapplied. Fig. 2 is a plan view of a portion of the jib; and Fig. 3 is aside elevation of a crane, showing a modification of the arrangement ofthe sheaves and hoisting chain or cable.

My improvements relate to that class of jibcranes in which the jib has avertically-adj ustable pivot or hinge connection at its lower end and anintermediate link connection with the mast, such as are shown in UnitedStates 'Letters Patent No. 254,941, dated March 14,

A represents the upright post or mast of a j ib-crane, which may be ofthe usual or any suitable construction. It is supported at the lower endor at both ends in any suitable manner, which will hold it securely inplace and permit of its turning on a vertical axis.

B is the jib, which has a vertically-adjustable pivot or hingeconnection at its lower end withthe mast, and is connected therewith atan intermediate point by one or more linksO, pivoted or hinged theretoand to the upper part of the mast, so as to permit of raising andlowering the lower end of the jib and thereby carrying its upper endfrom which the load is suspended in a horizontal line toward or from themast, as desired. Any suitable means may be employed for raising andlowering the lowerend of the jib and for securely connecting the samewith the mast. I have shown for the purpose a vertical screw D, whichhas suitable hearings in the mast and engages with a nut d, swiveled inthe lower end of the jib, so as to permit of the variation of the anglewhich the jib makes with the mast in raising and lowering the former, asabove mentioned, and is indicated by dotted lines illustrating differentpositions of the jib with reference to the mast. For turning the screwD, I have shown a crank E, which has bearings in the lower portion ofthe mast, and the shaft of which is provided with a bevel-pinion workingwith a similar pinion or gear on thelower end of the screw.

F is a hoisting-drum supported in suitable bearings formed in orattached to mast A at any convenient point, ordinarily near the base,and arranged to be operated by hand through a crankf or by any othersuitable power. It is obvious that a chain-wheel or other device forhauling in and letting out the chain or cable can be substituted for thewinding-drum.

G is the hoisting chain or cable attached to and arranged to wind upondrum F.

Referring now to Figs 1 and 2, the chain or cable G passes upwardly fromdrum F over a sheave I l,journaled in the upper end of the mastconcentric with the pivotal connection of link 0 therewith, thence inthe same direction around a sheave I, journaled in jib B, concentricwith the pivotal connection of link C therewith, thence under and over asheave M in jib B between its lower end and link 0, thence over a sheaveJ in the upper end of the jib, thence around a sheave K in the hook orlifting block L, and thence upwardly to a point at or near the upper endof the jib, where it is attached to a drum or segment of a drum N,concentric with and of the same radius as sheave J and rigidly attachedto said jib. The sheave lWI is set at a slight angle to a vertical planethrough jib B, with its lower side in line with sheave I. This al-. lowsthe chain or cable to pass from the top of sheave M to sheave J withoutinterference or contact with sheave I or that portion of the chain orcable between it and sheave H. By this arrangement of the sheaves andhoisting chain or cable the parts of said chain or ca ole leading fromonesheave to another are in every case parallelwith lines connecting thecenters of those sheaves. The extra wrap of the chain or cable G onsheave H, caused by lowering the lower end of jib B and moving its outerend in on a horizontal line toward the mast A, is exactly compensatedfor by less Wrap on sheave I, and the extra wrap on sheave J, caused bya like change in position of jib B, is compensated for by less wrap onthe segment N. his secures a perfectly-horizontal movement of the loadin extending or withdrawing the outer end of jib B more or less from ortoward the mast. Consequently by means of a crane of this class providedwith my improvements a load may be elevated to the desired height andthen swung horizontally around the axis of the mast and carriedhorizontally toward or from the mast into any desired position withoutraising or lowering it.

Referring now to Fig. 3,illustratinga modification of the arrangement ofthe hoisting chain or cable and the sheaves over which it passes, thechain or cable G passes over the sheave H, thence under the sheave I,thence over the sheave J in the upper end of the jib, thence around thesheave K in the hook or lifting-block L, and thence back to the upperend of the jib, to which it is secured. It is obvious that in place ofthe single sheave in the lifting-block L and in the upper end of the jiba greater number of sheaves may be employed to multiply the power of thehoisting apparatus, or the chain or cable as it hangs from the sheave Jmay be attached directly to the hook without the sheave K. By thisarrangement of the hoisting chain or cable and the sheaves around whichit passes the jib may be extended more or less at its upper end from themast without materially changing the vertical position of the liftingblock L and the load suspended therefrom. The only variation occurringin the vertical position of the load in carrying it horizontally towardand from the mast by raising and lowering the lower end of the jib, ashereinbefore mentioned, is due to a slightly increased or decreased wrapof the chain or cable around the sheaves over which it passes. Thisvariation, however, is entirely avoided by the arrangement of chain orcable and sheaves hereinbefore described and shown in Figs. 1 and 2.

I claim- 1. In a crane comprising a mast and jib, having avertically-adjustable hinge or pivotal connection at one end and anintermediate link connection therewith, the combination of sheaveslocated at the joints of the link with the mast and jib, a sheave at ornear the upper end of the jib, and a chain or cable passing over thesheave at the upper end of the link, around a sheave at the lower end ofthe link, and over the sheave at or near the upper end of thejib,substantially as and for the purposes set forth.

2. In a crane comprising a mast and jib, having a vertically-adjustablehinge or pivot connection at one end and an intermediate link connectiontherewith, the combination of sheaves located at the joints of the linkwith the mast and jib, a sheave at or near the upper end of the jib, alifting-block provided with a sheave, a hoisting device, and a chain orcable connected with said hoisting device and passing over the sheave atthe joint be tween said link and mast, around a sheave at the jointbetween said link and jib, over the sheave at or near the upper end ofthe jib,

around the sheave in the lifting-block, and back to the jib,substantially as and for the purposes set forth.

3. In a crane comprising a mast and jib, having a vertically-adjustablepivot or hinge connection at one end and an intermediate link connectiontherewith, the combination of sheaves located at the joints of the linkwith the mast and jib, a sheave at or near the upper end of the jib, asheave in the jib between its lower end and said link, and achain orcable passing over the sheave at the joint of the link and mast, thenceover the sheave at the joint of the link and jib, thence under thesheave toward the lower end of the jib, and thence over the sheave at ornear the upper end of the jib, substantially as and for the purposes setforth.

4. In a crane comprising a mast and jib, having a vertically-adjustablehinge or pivot connection at one end and an intermediate link connectiontherewith, the combination of sheaves located at the joints of the linkwith the mast and jib, a sheave at or near the upper end of the jib, adrum or segment of a drum rigidly secured to the jib concentric with andof the same radius as the sheave at or near its upper end, alifting-block provided with a sheave, and a chain or cable passing overthe sheave at the joint of the mast and link, thence around the sheaveat the jointof the link and jib, thence over the sheave at or near theupper end of the jib, thence around the sheave in the lifting-block, andback to said drum or segment, to which it is secured, substantially asand for the purposes set forth.

5. In a crane comprising a mast and jib, having a vertically-adjustablehinge or pivot connection at one end and an intermediate link connectiontherewith, the combination of sheaves located at the joints of the linkwith the mast and jib, a sheave at or near the upper end of the jib, asheave in the jib between its lower end and the joint of the link withthe jib, a drum or segment of a drum rigidly secured to the jibconcentric with and of the same radius as the sheave at or near itsupper end, a lifting-block provided with a sheave, a hoisting deviceattached to the mast, and a chain or cable con nected with said hoistingdevice and passing in the same direction over the sheaves at the jointsof the link with the mast and jib, thence under and over the sheavetoward the lower end of the jib, thence over the sheave at the upper endof the jib, thence around the sheave in the lifting-block,

IO and. thence back to said drum or segment of a drum, to which it issecured, substantially as and for the purposes set forth.

In testimony that I claim the foregoing as my own I affix my signaturein presence of two witnesses.

HARRY SAWYER.

Witnesses:

A. J. SHAW, J. G. EMERY, Jr.

